Berkeley has been notoriously charged with inconsistency because he held that spiritual substance exists, Although he argued against the existence of material substance. Berkeley is only inconsistent on the assumption that his argument in favor of spiritual substance parallels the rejected argument for material substance. I show that berkeley is relying on quite a different argument, One perfectly consistent with his theory of ideas, Based on presuppositions the germs of which can be found in the thought of his predecessors in (...) the theory of ideas, Descartes and locke. (shrink)